Les Cowley is publisher of the very popular website Atmospheric Optics (https://www.atoptics.co.uk). He is a specialist in both atmospheric and meteorological optics. And he is a world expert - perhaps the world expert - on the subjects of optical effects, light and color in nature, rainbows, halos, glories, green flashes and more. By training, he's a chemical physicist and has researched intermolecular forces, dynamics of chemical reactions and combustion phenomena. But on one winter’s afternoon in the 1970s he was dragged outside from all that to see an ice halo display. The sky was seemingly webbed and criss-crossed with delicate arcs. He did not know their names nor how they had formed but he was hooked. He now researches atmospheric phenomena and spreads this once-esoteric interest via websites and writings.